Coil problems

I have a '92 Galant VR-4. The coil is sparking badly between the 4-1 towers. I run Magnecor plug wires (8.5mm), have NGK's BPR6ES plugs in the car, and have thoroughly cleaned off all the connections with brake cleaner. I checked the resistance of all the plug wires (fine), and the coil towers themselves (fine). Still sparks.

I'm thinking the coil itself has gone south, but don't want to plunk down cash on a new one and be wrong. Any other ideas I should try?

Anything?